Effects Of Site Factors And Stand Characteristics On The Four Forest Pests In Heihe Area

The object of this study is about the four main forest pests in Heihe area,Heilongjiang:Coleophora obducta Meyrick.Malacosoma neustria testacea Motschulsky,Lymantria dispar asiatica Vnukovskij,Dendrolimus superans Butler.Set up 84 sample plots to carry out two aspects of research work.First,the investigation and analysis of the population density of these four kinds of forest pests from 2011 to 2013.Based on this,thr-ough One-way ANOVA,correlation analysis and multiple linear regression to establish mathematical regression model,two two correlation analysis,analyze site factors,stand characteristics and the biodiversity index in the plots of these four kinds of forest pests,and analyze the effects on these four kinds of forest pests average population density.The main prevention and control recommendations of these f-our kinds of forest pests were summed up through the analysis in Heihe area,Heilongjiang-To provide theoretical basis and reference value for the design of afforestation and sustainable management of forest resources,to provide guidance for biodiversity conservation.Analysis of C.obdzucta Meyrick.22 sample plots were investigated,it was found that the average population density of C.obdzucta Meyrick was significantly influenced by site factors such as slope position,aspect,gradient,elevation,stand characteristics,canopy density and forest types(P<0.05),whereas age of stands showed no significant influence on the average population of C.obducta Meyrick(P>0.05).The single variables of site factors,stand characteristics and the biodiversity index showed no significant influence on the average population of C.obducta Meyrick(P>0.05).The aspect and forest type demonstrated positive impact on the average population density of C.obducta Meyrick,but gradient,elevation,canopy density,age,Simpson index and Shannon-Wiener index of woody plant demonstrated negative effect on it.Analysis of M.neustria testacea Motschulsky,22 sample plots were investigated,it was found that the average population density of M.neustria testacea Motschulsky was significantly influenced by site factors such as aspect,elevation,stand characteristics,canopy density and proportion of Quercus mongolica Fisch.ex Ledeb.(P<0.05),whereas position of slope,gradient of stand characteristics showed no significant influence on the average population of M.neustria testacea Motschulsky(P>0.05).The single variables of site factors,stand characteristics,the biodiversity index showed no significant influence on the average population of M.neustria testacea Motschulsky(P>0.05).The slope position,aspect,Simpson index and Shannon-Wiener index demonstrated positive impact on the average population density of M.neustria testacea Motschulsky,but elevation,proportion of Quercus mongolica Fisch.ex Ledeb.demonstrated negative effect on it.Analysis of L.dispar asiatica Vnukovskij,22 sample plots were investigated,it was found that the average population density of L.dispar Linnaeus was significantly influenced by site factors such as slope position,aspect,gradient,elevation,stand characteristics such as canopy density,proportion of Quercus mongolica Fisch.ex Ledeb.(P<0.05).The single variables of site factors,stand characteristics,the biodiversity index showed no significant influence on the average population of L.dispar Linnaeus(P>0.05).The slope position and aspect demonstrated positive impact on the average population density of L.dispar Linnaeus,but gradient,elevation,canopy density,proportion of Quercus mongolica Fisch.ex Ledeb.,Simpson index and Shannon-Wiener index demonstrated negative effect on it.Analysis of D.superans Butler,18 the sample plots were investigated,it was found that the average population density of D.superans Butler was no significantly influenced by site factors such as slope position,aspect,gradient,elevation(P>0.05),whereas canopy density,forest types of stand characteristics showed significant influence on the average population of D.superans Butler(P<0.05).The single variables of site factors,stand characteristics,the biodiversity index showed no significant influence on the average population of D.superans Butler(P>0.05).The forest types and Simpson index demonstrated positive impact on the average population density of D.superans Butler,but slope position,aspect,gradient,elevation,canopy density,age,Shannon-Wiener index demonstrated negative effect on it.In afforestation nd greening work,the site selection of C.obducta Meyrick afforestation should avoid the light intensity and the flat,but slope L.dispar Linnaeus afforestation site should select the heavy grade to prevent the occurrence of C.obducta Meyrick and L.dispar asiatica Vnukovskij.In forest tending work,reasonable density and accelerate the forest canopy are effective methods for prevention and control of C.obducta Meyrick,M.neustria testacea Motschulsky and D.superans Butler.It is one of the effective method to reduce the population density of C.obducta Meyrick of forest tending on Lespedeza davurica(Laxm.)Schimdl and Rosa davurica Pall..